Pre Engineering Interview Question:

Tell me why is the use of granular sub-base in concrete carriageways not preferred?

Submitted by: Muhammad

Some of the reasons why granular sub-base is not preferred in concrete carriageways:
☛ Sub bases are permeable and hence water can seep through them easily. The soil particles get pumped out through the joints on the application of traffic loads. This results in the creation of voids underneath the pavement structure. This leads to the weakening of the concrete surface and it can crack easily upon intense traffic loads.
☛ Instead if lean concrete is used for carriageways it greatly increases the strength of the roads and the load carrying capacity of the roads is increased.
☛ Sub-bases implementation requires a lot of workmanship which can lead to an un-uniform distribution of the sub-base. This can lead to the cracking of the carriageway when there is severe traffic loading.
Submitted by: Muhammad